May 9, 2015
Sound Circuit | 3D Printing in the Classroom
One of the circuit groups in my class was given the task of making a circuit that produced sound. They came up with a really fantastic project. I like this group’s project for so many reasons.
When I was thinking through this group’s project I thought they would use this sound maker that came with our science curriculum. It is a really fun gadget that has a speaker and two dials. One that controls the volume, and one that controls the the pitch of the sound. Once you turn it on students can play with the sound and volume. All this group would have to do is cut the wires from the battery, reroute them to our switch box, and reconnect a switch.
They loved the gadget, but immediately wanted to do something more complicated. That seems to be a theme with this project. So we started brainstorming ideas and came up with using recordable greeting cards that we could take apart, record some music, and put back together on our bulletin board.
For some reason the recordable greeting cards never made it into the classroom, and they were left with trying to figure out what to do next. I started digging through my cupboards and found an old tape player that I salvaged before it got thrown out. I showed it to the students, and they loved it. It was a hilarious conversation. You would have thought they were looking at an item in a museum.
They started taking it apart and watching how it worked as I started looking for a cassette tape. When they had it all taken apart they decided to make a song on an iPad in the Garageband app. Then play it back while recording it on the tape player.
Watching them record a song they made on an iPad onto an old tape player was hilarious. I’m sure they were thinking “why don’t we just play this off of the iPad?”. After they had their song recorded they were able to play it back, and soon discovered one of the major draw backs to cassette tapes, “eating” the tape. Watching a 10 year old wind up a tape is not a sight one gets to see much any more.
The tape player began to have some problems too. They broke a fan belt that it needed to run and had to improvise with a rubber band. To their credit, the knew what the problem was and how to fix it. They also had to overcome the wiring on the tape player. There was many wires that didn’t need to be there for it to function the way they needed. They figured out which wires they needed and cut out the rest.
They were able to figure out where to inert a switch so that all that needs to be done is pressing a button and their song plays. I wouldn’t let them use the play button because I want the control for all of the circuits to go to one control panel or switch box. They solved this by keeping the play button pressed down, then putting a switch into the wires that connect the power. That way, when someone presses the button it gives power to the circuit and the music plays.
A couple of things that really impressed me with this group is how they were able to understand the purpose of the wires. There were many times that an important wire came loose and they were able to find where that happened and fix it on their own. The other thing that really impressed me was the leadership of one of the students. This project gave him an area to shine in. He took ownership of his work and stayed on topic better than he has all year. I’m looking forward to watching him present this to his parents.